In nursery operations it is often necessary to distribute individual seeds into a planting area, such as a nursery flat, with the seeds properly spaced from one another so that each will have sufficient space to develop. The proper spacing of the seeds is particularly significant where multicompartmented plug flats or multiple individual pots are seeded. To perform the task of seeding these nursery trays solely by hand is both time consuming and prone to error--e.g., the placement of multiple seeds where a single seed should be located or the omission of a seed from its place.
A variety of machines have been developed to automate the process of depositing seeds into their proper position in an array of a planting tray or flat. Such automated machines must be capable of separating individual seeds from a batch of seeds for further handling with minimal operator assistance, and the separated seeds must then be accurately positioned individually at their proper positions in the array, again, preferably, with minimal operator assistance. Because seeds can be quite small and are irregularly shaped, the task of separating and handling the seeds by machine is often formidable. The available machines that can successfully handle and distribute seeds of such varying size, weight, configuration, and surface characteristics are complex and expensive and require substantial maintenance. Because of the expense of such machines, their use has generally been limited to larger scale nurseries.